Apeliotus Technologies proposes to develop a commercial diagnostic for the early detection of age-related macular degeneration (ARMD). It relies on a functional test of dark adaptation kinetics (the transition from being light-adapted to being dark-adapted) that has been shown in previous work to detect the onset of ARMD at least four years before it is clinically evident. Testing is completely non-invasive and can be performed by an unskilled operator with a minimum of patient burden. ARMD is the leading cause of untreatable blindness for older adults in developed countries, affecting an estimated 30 million people worldwide and 13 million people in the US. The problem is expected to get significantly worse as the population ages. One challenge in addressing this health threat is the development of methods to discriminate normal aging from early (sub-clinical) disease onset. The proposed ARMD diagnostic has tremendous potential as a doctor's office screening tool for identification of at-risk and treatment populations. Equally important, it can provide a sensitive outcome measure for evaluating the early-stage impact of the many drugs and nutritional supplements being developed for ARMD. Developing these capabilities could result in substantially improved quality of life for older adults. The overall goal of this program is to demonstrate =90% sensitivity and =90% specificity for early-stage ARMD using the proposed diagnostic with a simple, rapid test protocol. The specific aim of this Phase I proposal is to demonstrate the feasibility of discriminating early-stage ARMD patients from normal old adults in = 20 minutes. A preliminary commercial prototype will be built with device parameters and a test protocol optimized for rapid determination of dark adaptation impairment, and a 40-person clinical study (20 early-stage ARMD patients; 20 normal old adults) will be conducted to confirm that discrimination is possible within the targeted time.